Modular heat exchangers for battery thermal modulation

ABSTRACT

A modular heat exchanger for battery thermal management having a plurality of similarly constructed heat exchange elements affixed to a cover plate and fluidly coupled with one another via a single external manifold structure that functions as both an inlet manifold and an outlet manifold for each of the heat exchange elements. Rigidity is improved with alternating tabs or overlapping tabs between adjacent elements, and/or side edges between adjacent elements having cutouts for receiving stiffening ribs formed in the cover plate. The external manifold structure provides additional stiffening for the interconnected heat exchange elements.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. Non-Provisional PatentApplication No. 16/660,708, entitled “MODULAR HEAT EXCHANGERS FORBATTERY THERMAL MODULATION”, and filed on Oct. 22, 2019. U.S.Non-Provisional Application No. 16/660,708 claims priority to U.S.Provisional Application No. 62/750,008, entitled “MODULAR HEATEXCHANGERS FOR BATTERY THERMAL MODULATION”, and filed on Oct. 24, 2018.The entire contents of each of the above-listed applications are herebyincorporated by reference for all purposes.

TECHNICAL FIELD

The present disclosure relates to heat exchangers for thermal managementof rechargeable batteries within an energy storage system of a batteryelectric vehicle (BEV) or hybrid electric vehicle (HEV), andparticularly to such heat exchangers having a modular construction andincluding multiple heat exchanger elements.

BACKGROUND AND SUMMARY

Energy storage systems such as those used in BEVs and HEVs compriserechargeable lithium-ion batteries. A typical rechargeable battery for aBEV or HEV will comprise a number of battery modules which areelectrically connected together in series and/or in parallel to providethe battery with the desired system voltage and capacity. Each batterymodule comprises a plurality of battery cells which are electricallyconnected together in series and/or parallel, wherein the battery cellsmay be in the form of pouch cells, prismatic cells or cylindrical cells.The operation of the battery may be endothermic or exothermic, dependingon temperature conditions.

A thermal modulation system for a rechargeable vehicle battery maycomprise a plurality of “cold plate” heat exchangers. Each cold platehas a flat upper surface on which one or more battery cells and/orbattery modules is supported, the cells and/or modules being in thermalcontact with a heat transfer fluid circulating through one or more fluidflow passages inside the cold plate.

A cold plate is commonly constructed from a cover plate defining theflat upper surface, and a shaped base plate having a plurality of ridgeswhich define the fluid flow passages, with the cover plate and baseplate being joined by brazing in a brazing furnace. A typical thermalmodulation system may comprise a plurality of such conventional coldplates joined together in series and/or parallel by conduits and fluidconnections.

It may be advantageous to replace multiple conventional cold plates witha smaller number of larger cold plates, to improve reliability andreduce cost and complexity, by reducing the number of components and thenumber of leak-prone fluid connections between cold plates. However,there are several limitations which practically limit the size ofconventionally constructed, brazed cold plates. For example, specializedequipment such as large presses are required for forming the ridges inlarge sized plates. In addition, the amount of energy required to heatthe cold plate components to brazing temperatures increases with size.Also, furnace size may also be limited, thereby making furnace brazingof large cold plates difficult and/or uneconomical.

It is known to braze a plurality of conventionally sized base plates,with ridges formed by conventional tooling, to a single flat top plate,thereby allowing the overall size of the heat exchanger to be somewhatincreased without incurring the added cost of re-tooling. This modularconstruction is known from commonly assigned U.S. patent applicationSer. No. 14/972,463, published as US 2016/0204486 A1, which isincorporated herein by reference in its entirety.

However, there is a continued need for improved modular constructionsfor battery heat exchangers such as cold plates, so as to increase sizeof the cold plates, to improve flexibility in designing cold plates forspecific applications, to improve reliability, and to allow for costeffective manufacture of larger cold plates.

To address at least some of the aforementioned problems, and inaccordance with an aspect of the present disclosure, there is provided aheat exchanger, comprising a plurality of heat exchanger elements. Eachof the heat exchanger elements preferably comprises: (i) a first platehaving an inner surface and an outer surface; (ii) a second plate havingan inner surface and an outer surface, wherein the first and secondplates are joined together with their inner surfaces in opposed facingrelation to one another, and with portions of the inner surfaces beingspaced apart from one another; (iii) at least one fluid flow passageadapted for flow of a heat transfer fluid, and located between thespaced apart portions of the inner surfaces of the first and secondplates; (iv) at least one first inlet port for supplying the heattransfer fluid to the plurality of fluid flow passages; and (v) at leastone first outlet port for discharging the heat transfer fluid from theplurality of fluid flow passages.

According to an aspect, the heat exchanger further comprises an externalmanifold portion comprising: (i) a second inlet port for supplying theheat transfer fluid to the external manifold portion; (ii) a secondoutlet port for discharging the heat transfer fluid from the externalmanifold portion; (iii) an inlet manifold channel in fluid communicationwith the at least one first inlet port of each heat exchanger elementand with the second inlet port of the external manifold portion; and(iv) an outlet manifold channel in fluid communication with the at leastone first outlet port of each heat exchanger element and with the secondoutlet port of the external manifold portion.

According to an aspect, the plurality of heat exchanger elements arearranged in a substantially planar array, and wherein the heat exchangerfurther comprises at least one stiffening elements arranged betweenadjacent heat exchanger elements in the array, to limit deflectionbetween the adjacent heat exchanger elements in the array.

According to an aspect, the second plate of each heat exchanger elementincludes a planar peripheral flange surrounding the at least one fluidflow passage; wherein the peripheral flange defines a sealing surfacealong which the inner surface of the second plate is sealingly joined tothe inner surface of the first plate; wherein the first plate has asealing surface along which the inner surface of the first plate issealingly joined to the sealing surface of the second plate; and whereinat least one of the first plate and the second plate includes a pair ofside edges, wherein the side edges of the second plate are defined byopposed outer edges of the peripheral flange.

According to an aspect, at least one of the side edges includes at leastone outermost edge portion, each of which extends along at least aportion of the side edge, and an innermost edge portion extending alongat least a portion of the side edge, wherein a first axis is definedalong the at least one outermost edge portion, and a second axis isdefined along the at least one innermost edge portion; wherein thesecond plates of the heat exchanger elements are arranged side-by-sidesuch that each of the second plates has at least one of its side edgespositioned with its first axis located between the first and second axesof the side edge of an adjacent one of the second plates, the side edgesof adjacent pairs of second plates being substantially co-planar withone another.

According to an aspect, the first and second axes are parallel to oneanother, and transverse to an axis along which the external manifoldextends.

According to an aspect, at least one of the side edges includes aplurality of outermost edge portions and a plurality of innermost edgeportions, wherein the outermost and innermost edge portions alternatewith one another along a length of the at least one side edge; whereinthe outermost edge portions and the innermost edge portions have acomplementary arrangement and shape, such that each of the outermostedge portions defines a male portion and each of the innermost edgeportions defines a female portion in which the male portion is received,so as to provide a plurality of stiffening elements; wherein a gap isprovided between adjacent pairs of side edges, the gap being tortuousand following along the innermost and outermost edge portions of theside edges.

According to an aspect, the first plates of the plurality of heatexchanger elements are integrally connected together to provide anintegral first plate to which all the second plates are sealinglyjoined; wherein the integral first plate has an area which is at leastas great as a combined area of the plurality of second plates.

According to an aspect, the first plates of the plurality of heatexchanger elements are separately formed, such that both the first plateand the second plate of each heat exchanger element include a pair ofsaid side edges; wherein, within each of the heat exchanger elements,each of the innermost edge portions of the first plate overlies one ofthe outermost edge portions of the second plate, and each of theoutermost edge portions of the first plate overlies one of the innermostedge portions of the second plate, so as to provide alternating upperand lower rows of projecting tabs along the side edges of the first andsecond plates; wherein, with the heat exchanger elements arrangedside-by-side in the array, an adjacent pair of the heat exchangerelements is arranged with the upper row of projecting tabs of a firstheat exchanger element overlapping the lower row of projecting tabs ofan adjacent second heat exchanger element, and with the upper row ofprojecting tabs of the second heat exchanger element overlapping thelower row of projecting tabs of the first heat exchanger element.

According to an aspect, the upper row of projecting tabs of the firstheat exchanger element is substantially co-planar with the upper row ofprojecting tabs of the second heat exchanger element; and wherein thelower row of projecting tabs of the first heat exchanger element issubstantially co-planar with the lower row of projecting tabs of thesecond heat exchanger element.

According to an aspect, the overlapping projecting tabs of the first andsecond heat exchanger elements are secured together.

According to an aspect, the first plates of the plurality of heatexchanger elements are separately formed, such that both the first plateand the second plate of each heat exchanger element include a pair ofside edges; wherein an upper or lower projecting tab is defined along atleast one side of each of the heat exchanger elements, each upperprojecting tab being formed by a portion of the first plate, inward ofone of the side edges of the first plate, projecting outwardly beyondthe side edge of the second plate, and each lower projecting tab beingformed by a portion of the second plate, inward of one of the side edgesof the second plate, projecting outwardly beyond the side edge of thefirst plate; wherein, with the heat exchanger elements arrangedside-by-side in the array, an adjacent pair of the heat exchangerelements is arranged with the upper projecting tab of a first heatexchanger element overlapping the lower projecting tab of an adjacentsecond heat exchanger element; and wherein each pair of upper and lowerprojecting tabs in overlapping arrangement comprises the at least onestiffening element.

According to an aspect, the upper projecting tab of the first heatexchanger element is substantially co-planar with the upper projectingtab of the second heat exchanger element; and/or wherein the lowerprojecting tab of the first heat exchanger element is substantiallyco-planar with the lower projecting tab of the second heat exchangerelement.

According to an aspect, the overlapping upper and lower projecting tabsof the first and second heat exchanger elements are secured together.

According to an aspect, the side edges of the second plates of adjacentheat exchanger elements are spaced apart from one another; wherein thefirst plates of the plurality of heat exchanger elements are integrallyconnected together to provide an integral first plate having an innersurface and an outer surface, wherein the second plates are sealinglyjoined to the inner surface of the integral first plate, and theintegral first plate has an area which is greater than a combined areaof the plurality of second plates; wherein the at least one stiffeningelement comprises a plurality of spaced apart ribs formed in the firstplate, and located between the side edges of adjacent heat exchangerelements.

According to an aspect, the ribs are elongated parallel to an axis whichis perpendicular to the side edges of the second plates; wherein theexternal manifold portion is provided along the outer surface of theintegral first plate; and wherein the external manifold portion extendsalong the axis which is perpendicular to the side edges of the secondplates.

According to an aspect, in each of the heat exchanger elements, thefirst plate has a pair of side edges and the first and second plates ofeach heat exchanger element are sealingly joined together; and whereinthe external manifold portion comprises a flattened tubular structureenclosing both the inlet manifold channel and the outlet manifoldchannel, the external manifold portion extending across all the heatexchanger elements along an axis which is perpendicular to the sideedges of the first and second plates; wherein the at least onestiffening element comprises a plurality of bends in the externalmanifold portion, wherein the bends creating first and second portionsof the external manifold portion which are located in different planesand which are separated by inclined shoulders; wherein the firstportions located in a first plane and the second portions located in asecond plane, the first and second planes being substantially paralleland spaced apart by approximately a thickness of the heat exchangerelements.

According to an aspect, each of the first portions extends along anouter surface of one of the second plates, and each of the secondportions is located in an aperture provided between an adjacent pair ofheat exchanger elements.

According to an aspect, each of the inclined shoulders is formed by apair of opposite bends proximate to the side edges of the first andsecond plates.

According to an aspect, each of the first portions of the externalmanifold portion is mechanically secured to one of the heat exchangerelements.

It should be understood that the summary above is provided to introducein simplified form a selection of concepts that are further described inthe detailed description. It is not meant to identify key or essentialfeatures of the claimed subject matter, the scope of which is defineduniquely by the claims that follow the detailed description.Furthermore, the claimed subject matter is not limited toimplementations that solve any disadvantages noted above or in any partof this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the present disclosure will now be described,by way of example, with reference to the accompanying drawings, inwhich:

FIG. 1A is a top perspective view of a cold plate heat exchangeraccording to a first embodiment;

FIG. 1B is a bottom plan view of a cold plate heat exchanger as in FIG.1A;

FIG. 2 is an exploded perspective view of a cold plate heat exchanger asin FIG. 1A;

FIG. 3 is a bottom plan view of a second plate of a heat exchanger as inFIG. 1A;

FIG. 4 shows the plates making up an external manifold portion of a heatexchanger as in FIG. 1A;

FIG. 5 is a partial, enlarged transverse cross-section through a heatexchanger as in FIG. 1A;

FIG. 6 is a partial bottom plan view of a heat exchanger as in FIG. 1A;

FIG. 7A is a partial bottom plan view of a prior art heat exchanger;

FIG. 7B is an enlarged cross-section of a prior art heat exchanger as inFIG. 7A;

FIG. 8 is a partial bottom plan view of a heat exchanger which is avariant of the heat exchanger of FIG. 1;

FIG. 9A is a partial bottom plan view of a heat exchanger which is avariant of a heat exchanger as in FIG. 1A;

FIG. 9B is a partial bottom plan view of a heat exchanger which is avariant of a heat exchanger as in FIG. 1A;

FIG. 10 is an exploded top perspective view of a heat exchangeraccording to an alternate embodiment;

FIG. 11 is a top plan view showing two second plates of a heat exchangeras in FIG. 10;

FIG. 12 is a perspective view of portions of a pair of adjacent heatexchanger elements of a heat exchanger according to an alternateembodiment;

FIG. 13 is a perspective view showing adjacent heat exchanger elementsas in FIG. 12 secured together.

FIG. 14 is a top perspective view of a heat exchanger according to analternate embodiment;

FIG. 15A is a bottom perspective view of a heat exchanger as in FIG. 14;

FIG. 15B is a perspective view showing two heat exchanger elements of aheat exchanger as in FIG. 14 joined together;

FIG. 15C is a close-up of a portion of two heat exchanger elementsjoined together as in FIG. 15B;

FIG. 16 is a top perspective view of a heat exchanger according to analternate embodiment;

FIG. 17 is a bottom perspective view of a heat exchanger as in FIG. 16;

FIG. 18 is a top perspective view of a heat exchanger according to analternate embodiment;

FIG. 19 is a bottom perspective view of a heat exchanger as in FIG. 18;

FIG. 20 is a bottom perspective view of a heat exchanger as in FIG. 18,with some heat exchanger elements removed; and

FIG. 21 is an enlarged close-up of a portion of an external manifoldportion of a heat exchanger as in FIG. 20.

DETAILED DESCRIPTION

The figures herein show example configurations with relative positioningof the various components. If shown directly contacting each other, ordirectly coupled, then such elements may be referred to as directlycontacting or directly coupled, respectively, at least in one example.Similarly, elements shown contiguous or adjacent to one another may becontiguous or adjacent to each other, respectively, at least in oneexample. As an example, components laying in face-sharing contact witheach other may be referred to as in face-sharing contact. As anotherexample, elements positioned apart from each other with only a spacethere-between and no other components may be referred to as such, in atleast one example. As yet another example, elements shown above/belowone another, at opposite sides to one another, or to the left/right ofone another may be referred to as such, relative to one another.Further, as shown in the figures, a topmost element or point of elementmay be referred to as a “top” of the component and a bottommost elementor point of the element may be referred to as a “bottom” of thecomponent, in at least one example. As used herein, top/bottom,upper/lower, above/below, may be relative to a vertical axis of thefigures and used to describe positioning of elements of the figuresrelative to one another. As such, elements shown above other elementsare positioned vertically above the other elements, in one example. Asyet another example, shapes of the elements depicted within the figuresmay be referred to as having those shapes (e.g., such as being circular,straight, planar, curved, rounded, chamfered, angled, or the like).Further, elements shown intersecting one another may be referred to asintersecting elements or intersecting one another, in at least oneexample. Further still, an element shown within another element or shownoutside of another element may be referred as such, in one example.

As an overview, FIGS. 1A, 1B, and 2 (and FIGS. 10 and 11) show exemplaryheat exchangers having a novel modular construction, which the presentinventors discovered (in various embodiments illustrated and describedherein) enables heat exchangers of different dimensions to beconstructed from a small (or smaller) number of parts and/or withsimplified manufacturing/construction techniques (as compared toexisting designs). FIG. 2 shows an exploded view of an exemplary heatexchanger comprising a substantially flat cover plate, a plurality ofsecond plates (each preferably stamped to define a plurality of fluidflow passages), and an external manifold portion adapted to providethermal regulating fluid (or heat transfer fluid) to each of the secondplates and to receive the thermal regulating fluid discharged from eachof the second plates, with the second plates sandwiched between thecover plate and the external manifold portion. FIG. 3 shows an exemplarysecond plate in greater detail, illustrating, for example, novelU-shaped or counterflow fluid flow paths developed by the presentinventors that provide improved heat transfer from/to a second platematerial and/or a heat transfer surface attached thereto. FIGS. 4 and 5show in greater detail various aspects of an exemplary external manifoldthat the present inventors discovered (in various embodiments disclosedherein) enables a single external manifold structure to function as bothan inlet manifold (to provide input fluid to a plurality of heatexchanger elements) and an outlet manifold (to receive output fluid fromthe plurality of heat exchanger elements). FIGS. 6, 7A, 7B, 8, 9A, and9B (and FIGS. 12 and 13) show various embodiments pertaining to what maybe referred to as jigsaw features (or cutouts and/or tabs and/oroverlapping tabs) along correspondingly mating edges of adjacent secondplates (with comparison to existing designs), which the presentinventors discovered avoid weaknesses between adjacent second plates.FIGS. 14, 15A, 15B, and 15C show embodiments having cutouts along sideedges (or side edges interrupted by cutouts) between adjacent secondplates, and FIGS. 16 and 17 show embodiments wherein stiffening ribs maybe formed in the first (cover) plate that extend into cutoutopenings/gaps along correspondingly mating edges of adjacent secondplates. Finally, FIGS. 18-21 show embodiments wherein a heat exchangercomprises a plurality of modules, each having a cover plate and a secondplate of substantially the same size/area, with an external manifoldportion (having bends to increase rigidity and stiffness)interconnecting the modules together.

Referring now to FIGS. 1A to 5, there is shown a cold plate heatexchanger 10 according to a first embodiment. Heat exchanger 10comprises a generally flat first plate 12 (also referred to herein as“cover plate”) having inner and outer surfaces 14, 16 and a plurality offormed second plates 18 (also referred to herein as “base plates”), eachhaving inner and outer surfaces 20, 22. The first plate 12 is shown asbeing transparent in FIG. 1A.

As illustrated in FIG. 2, the outer surface 16 of first plate 12 definesa generally flat surface upon which a plurality of battery cells and/orbattery modules 2 (FIG. 2) are stacked or supported, and which thereforeserves as the primary heat transfer surface of the heat exchanger 10. Inthe illustrated embodiment, the outer surface 16 of first plate iscompletely flat and free of any fluid fittings, manifolds, etc., andtherefore the entire surface area of outer surface is available for heattransfer with the battery cells and/or battery modules.

In preferred embodiments, heat exchanger 10 comprises a plurality ofheat exchanger elements 10′, each of which comprises the first plate 12,and one of the second plates 18. Therefore, in preferred embodiments,the first plates of the individual heat exchanger elements 10′ areintegrally connected together to provide integral first plate 12 towhich all the second plates 18 are sealingly joined. Preferably, theintegral first plate 12 has an area which is at least as great as thecombined area of the second plates 18.

As shown in FIG. 2, heat exchanger 10 includes five identical secondplates 18 and an integral first plate 12 which connects the heatexchanger elements into a single unit in which the heat exchangerelements 10′ are arranged as a substantially planar array. As will beappreciated, the first plate 12 (in some embodiments) is preferablycompletely flat and does not have any stamped features. Therefore, nospecialized equipment such as large presses are required for forming thefirst plate 12. The second plates 18 are of a size which permits them tobe economically produced by conventional forming equipment. The secondplates, for example, are preferably stamped to provide (and define or atleast partially define) a plurality of fluid flow passages. Where thesize of first plate 12 is too large to permit the heat exchanger 10 tobe joined together by furnace brazing, the second plates 18 may besealingly joined to the first plate 12 by laser welding.

As shown in FIG. 2, the first and second plates 12, 18 are joinedtogether with their inner surfaces 14, 20 in opposed facing relation toone another, and with portions of the inner surfaces 14, 20 being spacedapart from one another. For example, in one embodiment, each secondplate 18 has a central, generally planar base 24 surrounded by a raisedperipheral side wall 26 extending from the base 24 to a planarperipheral flange 28 defining a planar peripheral sealing surface 30 onthe inner surface 20 of second plate 18.

Preferably, each heat exchanger element further comprises at least onefluid flow passage 34 for flow of a heat transfer fluid, the at leastone fluid flow passage 34 being located between the spaced apartportions of the inner surfaces 14, 20 of the first and second plates 12,18. In this regard, the planar base 24 of second plate 18 is providedwith a plurality of spaced apart ribs 70 which define (in combinationwith inner surface 14 of first plate 12) the at least one fluid flowpassage 34. The ribs 70 extend upwardly out of the plane of the planarbase 24 and have a sufficient height such that the flat or rounded topsurface of each rib 70 defines a sealing surface which is substantiallyco-planar with the sealing surface 30 of planar flange 28. Duringassembly of heat exchanger 10, the sealing surface 30 of planar flange28 and the sealing surfaces of the ribs 70 are sealingly joined to theinner surface 14 of first plate 12, such that the inner surface 14 offirst plate 12 defines the top wall of the at least one fluid flowpassage 34, the planar base 24 of second plate 18 defines the bottomwall of the at least one fluid flow passage 34, and the ribs 70 andperipheral side wall 26 together define the sides of the at least onefluid flow passage 34.

As shown in FIG. 3, the second plates 18 each have a length (alongy-axis) and a width (along x-axis), and are shown as being elongate inthe length dimension. The ribs 70 are also elongated along the lengthdimension of the second plate 18, and the pattern of ribs 70 isconfigured to provide each heat exchanger element with a plurality offluid flow passages 34 defining a “counterflow” flow pattern, in which aplurality of cold channels and a plurality of hot channels are arrangedin an alternating orientation across the width (along x-axis) of thesecond plate 18.

The ribs 70 of each second plate 18 are preferably configured aselongated U-shapes, having a pair of elongated legs 72, 74 (alongy-axis) joined by a transverse rib portion 76. The ribs 70 are arrangedin two groups 78, 80 which are spaced apart from one another along thelength dimension of the second plate 18, with the ribs 70 of each group78, 80 being spaced apart across the width dimension of the secondplate. The closed ends of the U-shaped ribs 70 are located proximate tothe middle of second plate 18, while the open ends of ribs 70 arelocated proximate to the (lengthwise) ends of the second plate 18,spaced from the sidewall 26 and flange 28.

The fluid flow passages 34 each have an open first end 36 defined as aspace between a pair of adjacent U-shaped ribs 70 (or between a U-shapedrib 70 and the sidewall 26/flange 28), and a second end 38 locatedbetween the legs 72, 74 of one of the ribs 70, proximate to thetransverse rib portion 76. Each fluid flow passage 34 therefore has agenerally U-shaped configuration, with the flow changing direction in aturnaround area 82 defined between the open ends of the U-shaped ribs 70and the sidewall 26/flange 28 at the opposite ends of second plate 18.

Each second plate 18 further preferably comprises at least one firstinlet port 40 and at least one first outlet port 42. In one embodiment,the at least one first inlet port 40 comprises a continuous,transversely extending slot (along x-axis) through the second plate 18,which is located proximate to the middle of second plate 18, between thefirst and second groups 78, 80 of ribs 70. The central area of secondplate 18 between the two groups 78, 80 of ribs 70 therefore provides aninternal manifold area 84 within which fluid from the at least one firstinlet port 40 is distributed across the width of the second plate 18 andsupplied to the open first ends 36 of the fluid flow passages 34.

In one embodiment, the at least one first outlet port 42 comprises aplurality of apertures through the second plate 18, each of which isprovided at or proximate to the second end 38 of a fluid flow passage34, i.e. between the legs 72, 74 of one of the ribs 70, proximate to thetransverse rib portion 76.

Therefore, with this arrangement, it can be seen that each fluid flowpassage includes a cold channel (receiving cold fluid from first inletport 40) and a hot channel (discharging hot fluid to the first outletport 42), with the hot and cold channels being arranged in alternatingorder across the width of the second plate 18. It will be appreciatedthat the flow of heat transfer fluid can be reversed so that the firstinlet port 40 becomes the outlet port, and the first outlet port 42becomes the inlet. Furthermore, although each fluid flow passage 34 isdefined as a U-shaped passage which changes direction in turnaround area82, it will be appreciated that there will necessarily be some mixing offlow and transverse flow distribution between fluid flow passages 34 inthe turnaround area 82, since the fluid flow passages 34 are notseparated from one another in area 82.

As shown in FIG. 4 (and in FIG. 1B), heat exchanger 10 further comprisesan external manifold portion 44 which, in one embodiment, extendstransversely across the heat exchanger 10 and the second plates 18(along x-axis). The external manifold portion 44 comprises a secondinlet port 46 through which the heat transfer fluid is supplied to heatexchanger 10 through the external manifold portion 44, and a secondoutlet port 48 through which the heat transfer fluid is discharged fromthe heat exchanger 10 through the external manifold portion 44. Thesecond inlet and outlet ports 46, 48 may be provided with tubular fluidfittings (such as tubular fluid fitting 50, 52 shown in FIG. 20) topermit the second inlet and outlet ports 46, 48 to be connected to thebattery heating/cooling system of the vehicle (not shown).

The external manifold portion 44 further comprises an inlet manifoldchannel 54 in fluid communication with the at least one first inlet port40 of each heat exchanger element and with the second inlet port 46, andan outlet manifold channel 56 in fluid communication with the at leastone first outlet port 42 of each heat exchanger element and with thesecond outlet port 48. Therefore, the external manifold portion 44distributes and supplies the heat transfer fluid to each of the heatexchanger elements 40 through the second plate 18 thereof. The externalmanifold portion 44 also receives the heat transfer fluid from each heatexchanger element through the second plate 18 thereof, in order tocollect and discharge the heat transfer fluid from the heat exchangerelements.

As shown in FIG. 4, in one embodiment the external manifold portion 44is formed separately from the first and second plates 12, 18, and iscomprised of three plates sealingly joined together, and sealinglyjoined to the outer surfaces 22 (FIG. 3) of the second plates 18, forexample by mechanical sealing or by metallurgical bonding such asbrazing or welding. The three plates are identified herein as the innerplate 58, middle plate 60 and outer plate 62.

The inner plate 58 is preferably flat and provided with a plurality ofinlet apertures 64 and outlet apertures 66, which are shaped, sized andarranged on inner plate 58 so as to align with the first inlet andoutlet ports 40, 42 of the plurality of second plates 18.

The middle plate 60 preferably comprises a dished plate is provided withembossments in the form of elongate ribs which partly define the inletand outlet manifold channels 54, 56. In this regard, a centralembossment 86 is aligned with the central row of inlet apertures 64 ofinner plate 58, and has an open end 88 to permit the heat transfer fluidto enter the space enclosed by embossment 86 and inner plate 58. Themiddle plate 60 also includes a pair of outer embossments 90, each ofwhich is aligned with one of the two rows of outlet apertures 66 of theinner plate 58. The outer embossments 90 are joined at one end, with themiddle plate 60 being provided with an aperture 92 through which theheat transfer fluid is discharged from the pair of outer embossments 90.The areas enclosed between the outer embossments 90 (including theportion in which aperture 92 is formed) and the inner plate 58 definethe outlet manifold channel 56. It can be seen that the spaces betweenthe inner and outer embossments 86, 90 form part of the inlet manifoldchannel 54.

The outer plate 62 is preferably in the form of a dished plate whichnests with the middle plate 60, and is provided with a pair of openings,namely an outlet aperture 94 which aligns with the outlet aperture 92 inmiddle plate 60 and is open to the outlet manifold channel 56, and aninlet aperture 96 which is open to the inlet manifold channel 54. Theinlet aperture 96 defines the second inlet port 46 of the externalmanifold portion 44, and the aligned outlet apertures 92, 94 define thesecond outlet port 48 of the external manifold portion 44. In oneembodiment the second inlet and outlet ports 46, 48 are locatedproximate to one end of the external manifold portion 44, although itwill be appreciated that the locations of the ports 46, 48 can bevaried.

In one embodiment, heat transfer fluid is able to flow through inletaperture 96 and second inlet port 46 (of the external manifold portion44), through inlet manifold channel 54 (along the x-axis/transversedirection), and into open end 88 and the x-axis/transverse channelwithin central embossment 86. From central embossment 86 (of theexternal manifold portion 44), fluid is able to flow through inletaperture 64 and into the second plate 18 via first inlet port 40. Frominlet port 40, fluid is able to flow (primarily) in a lengthwise(y-axis) direction toward the ends of the second plate 18 via fluid flowpassage 34. Fluid may then turn around at the open ends of ribs 70 tothereafter flow back toward the middle of the second plate 18 and thoughfirst outlet port 42. From first outlet port 42 (of the second plate 18)fluid is able to flow into outlet aperture 66 (of the external manifoldportion 44) and through (x-axis/transverse running) outlet manifoldchannel 56. From outlet manifold channel 56 fluid is able to flow out ofthe external manifold via discharge outlet aperture 92 and outletaperture 94.

In preferred embodiments, the heat exchanger 10 further comprises atleast one stiffening element arranged between adjacent heat exchangerelements in the array, in order to limit deflection between the adjacentheat exchanger elements. The at least one stiffening element of heatexchanger 10 is now explained below with reference to FIGS. 6 to 8.

As mentioned above, the second plate 18 of each heat exchanger elementincludes a planar peripheral flange 28 surrounding the at least onefluid flow passage 34, and flange 28 defines a planar peripheral sealingsurface 30 along which the inner surface 20 of the second plate 18 issealingly joined to the inner surface 14 of the first plate 12. As shownin FIGS. 3 and 6, each second plate 18 has first and second side edges98, 100 defining the longer sides of the second plate 18 and extendingalong the y-axis. Each second plate 18 also has first and second endedges (extending between first side edge 98 and second side edge 100)defining the shorter sides of the second plate 18 and extending alongthe x-axis. In the array of heat exchanger elements making up heatexchanger 10, the side edges 98, 100 of all the second plates 18 are atleast generally parallel to one another, and the end edges of all thesecond plates 18 are at least generally parallel to one another.

The planar flange 28 includes relatively wide side portions (width ofside portions measured along x-axis) which extend along the side edges98, 100, and also includes relatively narrow end portions (width of endportions measured along y-axis) which extend along the end edges 102,104. The reason for the wider side portions of planar flange 28 willbecome apparent from the description below, although it will beappreciated that the width of the planar flange 28 at various areasaround the periphery of the second plate 18 can be varied from thatshown in the drawings.

Referring more specifically to the side edges 98, 100 of the secondplates 18, it can be seen that the width of the planar flange 28 alongthe side edges 98, 100 of second plate 18 (as measured along the x-axis)varies along the length of the side edges 98, 100 (as measured along they-axis).

As shown in FIG. 6, each of the side portions of the peripheral flange28 extending along the side edges 98, 100 of each second plate 18includes at least one outermost edge portion 106, each of the outermostedge portions 106 extending along at least a portion of the side edge 98or 100. A first axis A is defined along the at least one outermost edgeportion 108. In one embodiment, there is a plurality of outermost edgeportions 106 along each of the side edges 98, 100, the plurality ofoutermost edge portions 106 being spaced apart from one another alongthe length of the side edge 98 or 100. The outermost edge portions 106in one embodiment correspond to the widest areas (or tabs) in the sideportions of the peripheral flange 28.

Also as shown in FIG. 6, each of the side portions of the peripheralflange 28 extending along the side edges 98, 100 of each second plate 18also includes at least one innermost edge portion 108, each of theinnermost edge portions 108 extending along at least a portion of theside edge 98 or 100. A second axis B is defined along the at least oneinnermost edge portion 108. In one embodiment, there is a plurality ofinnermost edge portions 108 along each of the side edges 98, 100, theplurality of innermost edge portions 108 being spaced apart from oneanother along the length of the side edge 98 or 100. The innermost edgeportions 106 in one embodiment correspond to the narrowest areas (orcutouts, or knotches, each of which is adjacent to a wider area/tab) inthe side portions of the peripheral flange. The first and second axes A,B are parallel to one another and to axis-y.

As shown in FIG. 6, the second plates 18, 18′, 18″ of the heat exchangerelements are each in side-by-side arrangement along the x-axis, whereineach of the second plates 18, 18′, 18″ has at least one of its sideedges 98, 100 positioned with its first axis A, A′, A″ located betweenthe first and second axes of an adjacent one of the second plates. Forexample, the first axis A of second plate 18 is positioned between thefirst axis A′ and the second axis B′ of an adjacent second plate 18′ .Similarly, the first axis A′ of the second plate 18′ is positionedbetween the first axis A″ and second axis B″ of an adjacent second plate18″.

In the arrangement shown in FIG. 6, the outermost side edges 106 andinnermost side edges 108 alternate with one another along each of theside edges 98, 100. In each adjacent pair of second plates 18, theoutermost edge portions 106 and innermost edge portions 108 of theadjacent second plates 18 have a complementary arrangement and shape. Inthis regard, each of the outermost edge portions 106 defines a maleportion of the peripheral flange 28 and each of the innermost edgeportions 108 defines a female portion of peripheral flange 28. The maleportions defined by outermost edge portions 106 are arranged in opposedrelation to the female portions defined by the innermost edge portions108, and are shaped so as to be received in the female portions. In thisway, the side edges 98, 100 of adjacent second plates 18 do not overlapone another, but rather are interengaged, interlaced, or fit together injigsaw puzzle fashion, to define a non-linear joint line 110 between theside edges 98, 100 of adjacent second plates. Due to manufacturingtolerances, there will typically be a small gap 112 at the joint line110, and this gap 112 is similarly non-linear, since it follows theprofile of the alternating innermost and outermost portions 108, 106 ofside edges 98, 100. The shapes of joint line 110 and gap 112 depend onthe shapes of the innermost and outermost edge portions 108, 106, andmay be described as meandering, tortuous, zig-zag or jagged.

In one embodiment, the plurality of stiffening elements are defined bythe plurality of interlaced innermost and outermost edge portions 108,106, which provide the non-linear joint line 110 and gap 112, and thesestiffening elements increase rigidity between adjacent heat exchangerelements by eliminating a linear bending axis (or bend line)along/between the side edges 98, 100 of adjacent second plates 18. Inaddition, the provision of the non-linear joint line 110 and gap 112 mayprovide a more uniform joint between adjacent second plates 18, leadingto more uniform deflection during internal pressure cycles and externalloading.

The arrangement of is can be contrasted with prior art FIGS. 7A and 7B,showing side edges 98, 100 of a pair of adjacent second plates 18, 18′of a prior art heat exchanger as described in US 2016/0204486 A1.Similar reference numerals are used. As shown in FIG. 7A and 7B, the twosecond plates 18 are sealingly joined to a first plate 12. In prior artheat exchanger, the side edges 98, 100 are straight and parallel to eachother, and define a straight joint line 110 and a straight gap 112between the first side edge 98 of one second plate 18 and the secondside edge 100 of an adjacent second plate 18. In the gap 112, the heatexchanger is only one layer thick, i.e. being the thickness of firstplate 12. The linear joint line 110 and gap 112 define a linear bendingaxis along which there can be deflection of the adjacent heat exchangerelements, for example during shipping, handling, installation and/or useof the heat exchanger.

Referring back to FIG. 6, the innermost and outermost edge portions 108,106 of heat exchanger 10 are (as shown) rectangular, and provide each ofthe side edges 98, 100 with a series of rectangular castellations.However, it will be appreciated that other arrangements are possible.For example, as shown in FIG. 8, the side edges 98, 100 may have a morerounded arrangement so as to provide a joint line 110 and gap 112 whichhave a smoothly curved, meandering shape. In FIG. 8, adjacent secondplates 18, 18′ have side edges 98, 100 having wider (tab) areas 108 andnarrower (cut) areas 106, which are rounded and not rectangular as inFIG. 6.

The heat exchanger elements in FIG. 6 are arranged side-by-side, and notend-to-end. In other embodiments, the array may include heat exchangerelements arranged side-by-side, end-to-end, and/or end-to-side. Two suchembodiments are shown in FIGS. 9A and 9B. FIG. 9A shows a portion of aheat exchanger 10A in which there is a convergence of three secondplates 18 in side-by-side and side-to-end arrangements. FIG. 9B shows aportion of a heat exchanger 10B in which there is a convergence of foursecond plates 18 in side-by-side and end-to-end arrangements. In thesetypes of arrays, both the side edges 98, 100 and the end edges 102, 104of the second plates 18 may be provided with innermost and outermostedge portions.

FIGS. 10-11 show a heat exchanger 120 according to an alternateembodiment which shares a number of like elements with heat exchanger 10as in FIG. 1. These like elements are described with like referencenumerals and the following discussion will focus on differences betweenheat exchangers 10 (FIGS. 1) and 120 (FIG. 10).

As shown in FIG. 10, heat exchanger 120 comprises a first plate 12 and apair of second plates 18, forming two heat exchanger elements 10′. Eachsecond plate 18 has only one side edge 98 or 100 provided with innermost(cut) and outermost (tab) edge portions 106, 108 as described above (forsimilarly oriented cuts/cutouts and tabs), to provide a non-linear jointline 110 and gap 112 between the two second plates 18. Because eachsecond plate 18 has only one side edge 98 or 100 along which it isadjacent to another second plate 18, the innermost and outermost edgeportions 106, 108 are provided along only one side edge 98 or 100 ofeach second plate 18.

The second plates 18 include a pattern of ribs 70 which are configuredto provide each heat exchanger element with a plurality of fluid flowpassages 34 defining a “U-flow” flow pattern. The ribs 70 are linear andparallel, and are arranged in two groups 78, 80 which are spaced apartfrom one another along the length dimension of the second plate 18. Thecentral rib 70 in each group 78, 80 is labeled 70A in FIG. 11, having afirst end, near the middle of second plate 18, which is joined to a flowblocking embossment 122, and an opposite second end which terminates inturnaround area 82, and is spaced from the sidewall 26 and planar flange28 at one of the ends of the second plate 18.

The flow blocking embossment 122 separates an inlet manifold area 124from an outlet manifold area 126, and the central ribs 70A separate aninlet portion 128 and an outlet portion 130 of the second plate 18. Theremaining ribs 70 have first ends which terminate in either the inletmanifold area 124 or the outlet manifold area 126, and second ends whichterminate in the turnaround area 82. The ribs 70 separate the inlet andoutlet portions 128, 130 into individual fluid flow passages 34.

To provide structural support, the inlet and outlet manifold areas 124,126 and the turnaround areas 82 may be provided with additionalspaced-apart embossments such as dimples 132.

In heat exchanger 120 the external manifold portion 44 shown in FIG. 10is in the form of a flat tube closed along its sides and ends, andsealingly joined to the outer surface 16 of the first plate 12 andextending across the first plate 12, along the x-axis. The externalmanifold portion 44 includes inlet and outlet openings 46, 48 providedwith inlet and outlet fittings 50, 52. The surface of manifold portion44 which is in engagement with the outer surface 16 of first plate 12includes inlet and outlet apertures 64, 66 which are aligned and incommunication with fluid inlet and outlet openings 134, 136 of firstplate 12 (FIG. 10). The inlet openings 134 of first plate 12 providefluid communication between the inlet manifold area 124 and an inletmanifold channel 54 of the external manifold portion 44, and outletopenings 136 provide fluid communication between the outlet manifoldarea 126 and an outlet manifold channel 56 of the external manifoldportion 44. The inlet and outlet manifold portions 54, 56 of externalmanifold portion 44 are in flow communication with the respective inletand outlet ports 40, 42, and are separated from one another by adividing rib 68 extending along the x-axis. It can be seen that theinlet and outlet apertures 64, 66 of external manifold portion 44 arearranged on opposite sides of the dividing rib 68, and the fluid inletand outlet openings 134, 136 are staggered along the y-axis so as toalign with the inlet and outlet apertures 64, 66 of external manifoldportion 44. Instead of comprising a single flat tube with an internaldividing rib 68, it will be appreciated that the external manifoldportion 44 may comprise two separate flat tube structures enclosing therespective inlet and outlet manifold portions 54, 46.

FIGS. 12-13 illustrate portions of a heat exchanger 140 according to analternate embodiment. Heat exchanger 140 shares a number of likeelements with heat exchangers 10 and/or 120. These like elements aredescribed with like reference numerals.

Heat exchanger 140 comprises a plurality of heat exchanger elements140′, each comprising a first plate 12 and a second plate 18. In heatexchanger 140, the first plates 12 of the plurality of heat exchangerelements 140′ are separately formed, such that both the first plate 12and the second plate 18 of each heat exchanger element 140′ have atleast approximately the same area, the first plate 12 of each heatexchanger element 140′ including a pair of side edges 142, 144. With theheat exchanger elements 140′ arranged side-by-side, at least one sideedge 142 or 144 of the first plate 12 of one heat exchanger element 140′is in opposed facing relation, and substantially co-planar with, a sideedge 142 or 144 of an adjacent heat exchanger element 140′.

As described above with reference to heat exchanger 10 and 120, each ofthe second plates 18 of the heat exchanger elements 140′ is providedwith a plurality of alternating innermost and outermost edge portions106, 108 along at least one of its side edges 98, 100. According to oneembodiment, the first plates 12 of the heat exchanger elements 140′ aresimilarly provided with a plurality of alternating innermost andoutermost edge portions 106′, 108′ along at least one of its side edges142, 144.

At least one of the side edges 98, 100, 142, 144 of the first and secondplates 12, 18 in each heat exchanger element 140′ are configured suchthat each of the innermost edge portions 106′ of the first plate 12overlies (overlaps) one of the outermost portions 108 of the secondplate 18, and each of the outermost portions 108′ of the first plate 12overlies (overlaps) one of the innermost portions 106 of the secondplate 18. It can be seen from FIG. 12 that upper and lower rows ofprojecting tabs are thus formed along the side edges 98, 100, 142, 144of the first and second plates 12, 18, wherein at least one side of eachheat exchanger element 140′ is formed in this fashion. Each of theprojecting tabs of the upper row comprises an outermost portion 108′ ofone of the first plates 12, and each of the projecting tabs of the lowerrow comprises an outermost portion 108 of one of the second plates 18.

With the heat exchanger elements 140′ arranged in a side-by-side array,as in heat exchangers 10 and 120, each adjacent pair of heat exchangerelements 140′ is arranged with the upper row of projecting tabs of oneof the heat exchanger elements 140′ overlapping the lower row ofprojecting tabs of the other heat exchanger element 140′, and viceversa. In this way, the side edges 98, 100, 142, 144 the first andsecond plates 12, 18 of adjacent heat exchanger elements 140′ areinterengaged, interlaced, or fit together in jigsaw puzzle fashion, todefine non-linear joint lines 110 between the side edges 98, 100 ofadjacent second plates 18, and similar non-linear joint lines 110′between the side edges 142, 144 of adjacent first plates 12.Furthermore, the overlapping projecting tabs provided by the outermostedge portions 108′, 108 of the first and second plates 12, 18 provide aninterlocking connection between the side edges 98, 100, 142, 144, andprovide surfaces along which the side edges 98, 100, 142, 144 may besecured together, for example by welding or by mechanical fastening,either with fasteners such as rivets, or without fasteners, for exampleby press-joining. FIG. 13 shows weld joints 146 through the overlappingoutermost edge portions 108′, 108.

FIGS. 14-15C illustrate a heat exchanger 150 according to an alternateembodiment. Heat exchanger 150 shares a number of like elements withheat exchangers 10, 120 and/or 140. These like elements are describedwith like reference numerals.

Heat exchanger 150 comprises a plurality of heat exchanger elements150′, each comprising a first plate 12 and a second plate 18. In heatexchanger 150, the first plates 12 of the plurality of heat exchangerelements 150′ are separately formed, such that both the first plate 12and the second plate 18 of each heat exchanger element 150′ have atleast approximately the same area, the first plate 12 of each heatexchanger element 150′ including a pair of side edges 152, 154. With theheat exchanger elements 150′ arranged side-by-side, at least one sideedge 152 or 154 of the first plate 12 of one heat exchanger element 150′is in opposed facing relation, and substantially co-planar with, a sideedge 152 or 154 of an adjacent heat exchanger element 150′ . Heatexchanger 150 further comprises an external manifold portion 44 whichextends transversely across the heat exchanger 150 and specificallyacross the outer surfaces 16 of the first plates 12 (along x-axis), andis similar or identical in structure to external manifold portion 44 ofheat exchanger 120 described above.

The external manifold portion 44 of heat exchanger 150 comprises a flattube closed along its sides and ends, and sealingly joined to the outersurface 16 of the first plate 12 and extending across the first plate12, along the x-axis. The external manifold portion 44 includes inletand outlet openings 46, 48 (not shown) provided with inlet and outletfittings 50, 52. Although not shown, the surface of manifold portion 44which is in engagement with the outer surface 16 of first plate 12includes inlet and outlet apertures 64, 66 on opposite sides of adividing rib (such as diving rib 68 shown in FIG. 10), the apertures 64,66 being aligned and in communication with respective fluid inlet andoutlet openings 134, 136 of first plate 12, as in heat exchanger 120.

An upper projecting tab 156 or a lower projecting tab 158 is definedalong at least one side of each heat exchanger element 150′. Each upperprojecting tab 156 comprises a portion of the first plate 12, locatedinwardly of one of the side edges 152 or 154, and projecting outwardlybeyond the side edge 98 or 100 of the second plate 18. Conversely, eachlower projecting tab 158 comprises a portion of the second plate 18,located inwardly of one of the side edges 98, 100, and projectingoutwardly beyond the side edge 152 or 154 of the first plate 12.

With the heat exchanger elements 150′ arranged in a side-by-side array,as in heat exchangers 10, 120 and 140, each adjacent pair of heatexchanger elements 150′ is arranged with the upper projecting tab 156 ofone of the heat exchanger elements 150′ overlapping the lower projectingtab 158 of the other heat exchanger element 150′. In this way, theoverlapping side edges 98, 100, 152, 154 the first and second plates 12,18 of adjacent heat exchanger elements 150′ are overlapped to provide alap joint between adjacent heat exchanger elements 150′ and providesurfaces along which the side edges 98, 100, 152, 154 may be securedtogether, for example by welding or by mechanical fastening, either withfasteners such as rivets, or without fasteners, for example bypress-joining. FIG. 15A shows weld joints 160 through the overlappingupper and lower tabs 156, 158.

It will be appreciated that the upper and lower tabs 156, 158 may eitherextend continuously along the side edges 98, 100, 152, 154, or they maybe discontinuous, for example being interrupted by cutouts 162 as shownin FIGS. 14, 15A and 15B (and cutout 62 in FIG. 15C).

Each of the heat exchanger elements 140′, 150′ of heat exchangers 140and 150 may be similar or identical in size and shape to conventionalbrazed cold plate heat exchangers, thereby allowing the heat exchangerelements 140′, 150′ to be manufactured in a conventional manner, usingconventional shaping equipment and furnace brazing. The heat exchangerelements 140′, 150′ can then be secured together side-by-side in themanner described above to form heat exchangers 140, 150 having aplurality of heat exchanger elements 140′, 150′, and provided withexternal manifold portions as described herein. Similar end-to-endjoining of heat exchanger elements 140′, 150′ can be accomplished byproviding the end edges of first and second plates 12, 18 with similarlyformed projecting tabs as described above with reference to side edges98, 100, 142, 144, 152, 154.

FIGS. 16-17 illustrate a heat exchanger 170 according to an alternateembodiment. Heat exchanger 170 shares a number of like elements withheat exchangers 10, 120, 140 and/or 150. These like elements aredescribed with like reference numerals.

Heat exchanger 170 comprises a plurality of heat exchanger elements170′, each comprising a first plate 12 and a second plate 18. As in heatexchangers 10 and 120, heat exchanger 170 includes a single, integralfirst plate 12 to which a plurality of second plates 18 are sealinglyjoined in side-by-side arrangement. The second plates 18 of heatexchanger 170 are generally similar to the second plates 18 of heatexchanger 120 described above, each second plate 18 having side edges98, 100, and having a pattern of ribs 70 which are configured to provideeach heat exchanger element 170′ with a plurality of fluid flow passages34 defining a “U-flow” flow pattern. The ribs 70 are linear andparallel, and are arranged in two groups 78, 80 which are spaced apartfrom one another along the length dimension of the second plate 18. Thecentral rib 70 in each group 78, 80 is labeled 70A, having a first end,near the middle of second plate 18, which is joined to a flow blockingembossment 122.

In heat exchangers 10 and 120, the spacing between the side edges 98,100 of adjacent second plates 18 is minimized. In contrast, the sideedges 98, 100 of second plates 18 of heat exchanger 170 areintentionally spaced apart across the inner surface 14 of first plate12, along the x-axis. In the spaces along the sides of second plates 18and between adjacent second plates 18 there are provided stiffeningelements in the form of stiffening ribs 172. In particular, there is aplurality of such stiffening ribs 172 between each adjacent pair ofsecond plates 18, wherein the stiffening ribs 172 between each pair ofsecond plates 18 are spaced apart and arranged in a row along they-axis.

The stiffening ribs 172 are formed as embossments in the first plate 12,and at least some of the ribs 172 may be elongated parallel to an axis(the x-axis) which is perpendicular to the side edges 98, 100 of thesecond plates 18. Alternatively, at least some of the ribs 172 may becircular or any other convenient shape. In one embodiment, the outersurfaces 22 of second plates 18 form the surfaces on which the batterycells and/or modules are supported, and the embossments comprisingstiffening ribs 172 are formed so as to protrude from the outer surface16 of the first plate 12, i.e. away from the surfaces on which thebattery cells and/or modules are supported.

In addition to being embossed with stiffening ribs 172, the first plate12 of heat exchanger 170 differs from the flat first plates 12 of heatexchangers 10 and 120 in other important respects. In this regard, thefirst plate 12 is formed of two plate layers, including an inner platelayer 174 (FIG. 16) defining the inner surface 14 of first plate 12, andan outer plate layer 176 (FIG. 17) defining the outer surface 16 offirst plate 12. Also, the external manifold portion 44 is integratedwith the first plate 12, with the outer plate layer 176 including a pairof elongate embossments 178, 180, wherein the inlet and outlet manifoldchannels 54, 56 are formed between the inner plate layer 174 and theembossments 178, 180 of the outer plate layer 176, and with the inletand outlet ports 40, 42 being provided through the first plate 12 asshown in FIG. 16. The inlet and outlet ports 40, 42 may be provided withfittings (not shown), which may extend from the inner surface 14 offirst plate 12. Although not visible in the drawings, the inner platelayer 174 has inlet and outlet manifold openings in communication withthe fluid flow passages 34 defined between the first plate 12 and thesecond plates 18. The embossments 178, 180 and the external manifoldportion 44 of heat exchanger 170 extend along the x-axis, i.e. the axiswhich is perpendicular to the side edges 98, 100 of the second plates18, and therefore also serve to enhance the stiffness of the heatexchanger 170 along the x-axis.

The heat exchanger 170 according to one embodiment may be constructed bywelding together inner and outer plate layers 174, 176 to provide thefirst plate 12 and external manifold portion, and by welding togetherthe second plates 18 and the first plate 12. Instead of having twolayers 174, 176 with an integrally formed external manifold portion 44,it will be appreciated that the first plate 12 may comprise a singlelayer, and the external manifold portion 44 may be formed separatelyfrom first plate 12, as in the embodiments described above. Also,instead of comprising two separate embossments 178, 180, the externalmanifold portion 44 may comprise a single flat tube with an internaldividing rib, as in the external manifold portions 44 of heat exchangers120 and 150 described above.

FIGS. 18-21 illustrate a heat exchanger 190 according to an alternateembodiment. Heat exchanger 190 shares a number of like elements withheat exchangers 10, 120, 140, 150 and/or 170. These like elements aredescribed with like reference numerals.

Heat exchanger 190 is similar to heat exchangers 140 and 150 in that itcomprises a plurality of heat exchanger elements 190′, each comprising afirst plate 12 and a second plate 18. In heat exchanger 190, the firstplates 12 of the plurality of heat exchanger elements 190′ areseparately formed, such that both the first plate 12 and the secondplate 18 of each heat exchanger element 190′ have at least approximatelythe same area, the first plate 12 of each heat exchanger element 190′including a pair of side edges 192, 194. With the heat exchangerelements 190′ arranged side-by-side, at least one side edge 192 or 194of the first plate 12 of one heat exchanger element 190′ is in opposedfacing relation, and substantially co-planar with, a side edge 192 or194 of an adjacent heat exchanger element 190′.

The first plates 12 of heat exchanger 190 are flat and the outersurfaces 16 of the first plates 12 define the surfaces on which thebattery cells and/or modules are supported. The second plates 18 aresimilar to those of heat exchanger 170 described above, each secondplate 18 having side edges 98, 100, and having a pattern of ribs 70which are configured to provide each heat exchanger element 190′ with aplurality of fluid flow passages 34 defining a “U-flow” flow pattern.The rib structure of heat exchanger elements 190′ is relatively simple,however, in that only includes two central ribs 70, each having a firstend, near the middle of second plate 18, which is joined to a flowblocking embossment 122.

Heat exchanger 190 differs from heat exchangers 140, 150 in that the atleast one stiffening element between adjacent heat exchanger elements190′ in the side-by-side array do not necessarily include anyconnections between adjacent heat exchanger elements 190′, in the mannerof heater exchangers 140, 150 discussed above. Rather, in heat exchanger190, the at least one stiffening element between adjacent heat exchangerelements 190′ is provided by the external manifold portion 44, asdescribed below.

In this regard, the external manifold portion 44 comprises a flattenedtubular structure enclosing both the inlet manifold channel 54 and theoutlet manifold channel 56, separated by an internal dividing rib (suchas dividing rib/internal barrier 208). The external manifold portion 44extends across all the heat exchanger elements 190′ along an axis (thex-axis) which is perpendicular to the side edges 192, 194 of the firstplate 12 and the side edges 98, 100 of the second plate 18.

The at least one stiffening element of heat exchanger 190 comprises aplurality of bends in the external manifold portion 44, wherein thebends are arranged to separate a plurality of first and second portionsof the external manifold portion 44. For example, in the illustratedembodiments, the external manifold portion 44 includes a plurality offirst portions 196, each of which is flat and planar, and extends alongthe outer surface 16 of the first plate 12 of one of the heat exchangerelements 190′. The first portions 196 are all substantially co-planarwith one another.

The external manifold portion 44 also includes a plurality of secondportions 198 which are substantially co-planar with one another, theplane of the first portions 196 being substantially parallel to andspaced from the plane of the second portion 198 by an amount which isabout the same as the thickness of the heat exchanger element 190′. Inthe illustrated embodiment, the second portions 198 may be substantiallyco-planar with the outer surfaces of the second plates 18.

As best seen in FIGS. 20 and 21, the first and second portions 196, 198are separated by inclined shoulders 200, each of which is formed by apair of opposite bends 202, 204 (FIG. 21) proximate to the side edges98, 100, 192, 194 of the first and second plates 12, 18.

The side edges 98, 100, 192, 194 have inwardly extending portions 205near the middle of each heat exchanger element 190′, such that apertures206 (FIG. 19) are provided between the middle portions of adjacent heatexchanger elements 190′. The second portions 198 of the externalmanifold portion 44 are received in these apertures 206.

As shown in FIG. 20, the inlet and outlet manifold channels 54, 56 ofexternal manifold portion 44 may be separated by an internal barrier208, and the inlet and outlet apertures 64, 66 of the external manifoldportion 44 are formed on either side of the internal barrier 208, incommunication with inlet and outlet ports formed through the first plate12 (not shown). To enable mechanical connection of the external manifoldportion 44 to the heat exchanger elements 190′, resilient sealingelements such as 0-rings 210 are provided between the inlet and outletapertures 64, 66 of the external manifold portion 44 and the inlet andoutlet ports of the first plate 12. Also, fastener holes 212, 214 areprovided through the respective external manifold portion 44 and theheat exchanger elements 190′. The holes 212, 214 are adapted to receivefasteners (not shown) such as screws or bolts, for fastening themanifold portion 44 and heat exchanger elements 190′ together, andoptionally for fastening the heat exchanger 190 to a support structure(not shown).

The fastener holes 212 of the external manifold portion 44 may extendthrough the second portions 198, for example through the internalbarrier 208 and proximate to the inlet and outlet apertures 64, 66. Thefastener holes 214 of the heat exchanger elements 190′ may extendthrough the first plate 12 and through the flow-blocking embossment 122in the second plate 18.

The external manifold portion 44 is also provided with first and secondtubular fittings 50, 52 for connection to the battery heating/coolingsystem of the vehicle (not shown).

It will be appreciated that each of the heat exchangers described hereinmay optionally be provided with one or more electric heating element(such as, for example, an electric heating element) for heating the heattransfer fluid (or thermal regulating fluid) flowing through the heatexchanger, and/or with one or more chiller (or cooling element) (suchas, for example, an electric cooling element) for cooling the heattransfer fluid flowing through the heat exchanger.

It will be appreciated that the configurations and routines disclosedherein are exemplary in nature, and that these specific embodiments arenot to be considered in a limiting sense, because numerous variationsare possible. The subject matter of the present disclosure includes allnovel and non-obvious combinations and sub-combinations of the varioussystems and configurations, and other features, functions, and/orproperties disclosed herein.

As used herein, the terms “approximately” is construed to mean plus orminus five percent of the range unless otherwise specified.

The following claims particularly point out certain combinations andsub-combinations regarded as novel and non-obvious. These claims mayrefer to “an” element or “a first” element or the equivalent thereof.Such claims should be understood to include incorporation of one or moresuch elements, neither requiring nor excluding two or more suchelements. Other combinations and sub-combinations of the disclosedfeatures, functions, elements, and/or properties may be claimed throughamendment of the present claims or through presentation of new claims inthis or a related application. Such claims, whether broader, narrower,equal, or different in scope to the original claims, also are regardedas included within the subject matter of the present disclosure.

While various embodiments have been described in connection with thepresent disclosure, it will be understood that certain adaptations andmodifications of the described exemplary embodiments can be made asconstrued within the scope of the present disclosure. Therefore, theabove discussed embodiments are considered to be illustrative and notrestrictive.

1. A heat exchanger, comprising: a plurality of heat exchanger elements,wherein each of the plurality of heat exchanger elements comprises: afirst plate of a plurality of first plates and a second plate of aplurality of second plates each comprising an inner surface and an outersurface, wherein the plurality of first plates and the plurality ofsecond plates are joined together with their inner surfaces in opposedfacing relation to one another, and with portions of the inner surfacesbeing spaced apart from one another; wherein side edges of the secondplate of adjacent heat exchanger elements are spaced apart from oneanother, wherein the first plates of the plurality of heat exchangerelements are integrally connected together to provide an integral firstplate having an inner surface and an outer surface, wherein the secondplates are sealingly joined to the inner surface of the integral firstplate, and the integral first plate has an area which is greater than acombined area of the plurality of second plates, wherein at least onestiffening element comprises a plurality of ribs formed in the firstplate and located between the side edges of adjacent heat exchangerelements.
 2. The heat exchanger of claim 1, wherein the plurality ofribs is elongated parallel to an axis which is perpendicular to the sideedges of the second plates, wherein an external manifold portion isprovided along the outer surface of the integral first plate, andwherein the external manifold portion extends along an axis which isperpendicular to side edges of the second plates.
 3. The heat exchangerof claim 1, wherein the plurality of ribs is formed in the first plateand extend into cutout openings along correspondingly mating edges ofadjacent second plates.
 4. The heat exchanger of claim 1, wherein atleast one side edge of the first plate of one heat exchanger element isin opposed facing relation and co-planar with a side edge of an adjacentheat exchanger element.
 5. The heat exchanger of claim 1, furthercomprising an external manifold portion extending transversely acrossthe heat exchanger and across outer surfaces of the first plates alongan axis.
 6. The heat exchanger of claim 5, wherein the external manifoldportion comprises a flat tube closed along its sides and ends andsealingly joined to the outer surface of the first plate along the axis.7. The heat exchanger of claim 5, wherein the external manifold portioncomprises inlet and outlet openings comprising inlet and outletfittings.
 8. The heat exchanger of claim 5, wherein a surface of theexternal manifold portion is in engagement with the outer surface of thefirst plate and comprises inlet and outlet apertures on opposite sidesof a dividing rib, wherein the dividing rib is arranged on the firstplate, wherein the first plate is a cover plate and the second plate isa base plate.
 9. The heat exchanger of claim 1, further comprising aplurality of upper projecting tabs and a plurality of lower projectingtabs, where each of the plurality of upper projecting tabs comprises aportion of the first plate located inwardly of at least one side edge,and each of the plurality of lower projecting tabs comprises a portionof the second plate located inwardly of at least one side edge.
 10. Theheat exchanger of claim 9, wherein each adjacent pair of heat exchangerelements of the plurality of heat exchanger elements is arranged with anupper projecting tab of the plurality of upper projecting tabs of one ofthe adjacent pair of heat exchanger elements overlapping a lowerprojecting tab of the plurality of lower projecting tabs of the other ofthe adjacent pair of heat exchanger elements.
 11. The heat exchanger ofclaim 10, wherein overlapping side edges of the first plate and thesecond plate of adjacent heat exchanger elements are a lap joint. 12.The heat exchanger of claim 11, wherein the lap joint provides surfacesalong which side edges may be physically coupled via welding ormechanical fastening.
 13. A heat exchanger, comprising: a plurality ofheat exchanger elements, wherein each of the plurality of heat exchangerelements comprises: a first plate of a plurality of first plates and asecond plate of a plurality of second plates each comprising an innersurface and an outer surface; wherein in each of the heat exchangerelements, the first plate has a pair of side edges and the first andsecond plates of each heat exchanger element are sealingly joinedtogether, and wherein an external manifold portion comprises a flattenedtubular structure enclosing both an inlet manifold channel and an outletmanifold channel, the external manifold portion extending across all theheat exchanger elements along an axis which is perpendicular to sideedges of the first and second plates, wherein at least one stiffeningelement comprises a plurality of bends in the external manifold portion,the plurality of bends creating first and second portions of theexternal manifold portion which are located in different planes andwhich are separated by inclined shoulders, wherein the first portionslocated in a first plane and the second portions located in a secondplane, the first and second planes being parallel and spaced apart by athickness of the plurality of heat exchanger elements.
 14. The heatexchanger of claim 13, wherein the plurality of bends in the externalmanifold portion interconnect adjacent modules.
 15. The heat exchangerof claim 13, wherein each of the first portions extends along the outersurface of one of the second plates, and each of the second portions islocated in an aperture provided between an adjacent pair of heatexchanger elements.
 16. The heat exchanger of claim 13, wherein each ofthe inclined shoulders is formed by a pair of opposite bends proximateto the side edges of the first and second plates.
 17. The heat exchangerof claim 13, wherein each of the first portions of the external manifoldportion is mechanically secured to one of the heat exchanger elements.18. A heat exchanger, comprising a plurality of heat exchanger elements,each comprising a first plate and a second plate; wherein side edges ofthe second plate of adjacent heat exchanger elements are spaced apartfrom one another via cutouts; and the first plate comprises a pluralityof ribs that extend into the cutouts along mating edges of adjacentsecond plates.
 19. The heat exchanger of claim 18, further comprising anexternal manifold portion extending transversely across outer surfacesof the first plates, wherein the external manifold portion is inengagement with an outer surface of the first plate and comprises inletand outlet apertures on opposite sides of a dividing rib.
 20. The heatexchanger of claim 19, wherein the dividing rib is parallel to alongitudinal axis of the external manifold portion.